Clock dial



Sept. 30, 1958 H. MCLEOD ET AL 2,853,850

CLOCK DIAL Filed Jan. 13, 1956 In venan?. Helen M'LeocZ, A bert L. Tay on (yu/l, mlrl/ AMS.

United States Patent O CLOCK DIAL Helen McLeod, Wakefield, and Albert L. Taylor, Melrose, Mass.

Application January 13, 1956, Serial No. 558,984

2 Claims. (Cl. 58-128) This invention relates to clocks and other time measuring devices and more particularly to an improved dial adapted (l) to indicate expiration of predetermined time intervals or (2) to provide a measurement of elapsed time.

While a c-onventional clock dial, that is, a dial whose time scale runs clockwise, is adapted to provide a measurement of elapsed time, it is not very well suited for perceiving when a predetermined time interval has elapsed or -for obtaining a direct indication as to how muchL of a predetermined time interval remains unexpired. For the latter purposes it is handier to employ a time piece having dials provided with a time scale that runs counter to the direction of movement of the hours and minute hands. Generally, a .person is able to purchase a clock or watch having either one or the other type of dial but not both.

Accordingly, it is the object of this invention to provide a dial for clocks or watches that comprises a time measuring scale whose numbers in progressively increasing values are arranged in clockwise order and a timer scale whose numbers are arranged in counterclockwise order.

A further object of this invention is to provide a time indicator comprising a fixed dial having two sets of circularly arranged quantity figures, the figures of one set increasing in value in a clockwise direction and the figures of the second set increasing in value in a counterclockwise direction, the figures of one set being angularly displaced from the adjacent figure of the second set, and a rotatable dial mounted coaxially with said fixed dial having a plurality of radially spaced openings, each characterized by a pair of straight radially extending sides, and a plurality of graduated indicants thereon, said rotatable dial Vbeing rotatable from a first position wherein the figures of said first set are displaced through said openings and the figures of said second set are hidden behind the body `of said second dial to a second position wherein said second set of figures is displayed through said openings and said first set is hidden by the body of said second dial.

Other objects and many of the attendant advantages of this invention will be :readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

Fig. l is a front elevation of a dial constructed according to this invention as it appears when attached to a clock (shown in phantom);

Fig. 2 is an enlarged front elevation of the rear or fixed dial element;

Fig. 3 is an enlarged front elevation of the rotatable dial or shutter element;

Fig. 4 is an enlarged front elevation showing the iixed and rotatable dial elements secured together in rotatable relation; and

Fig. 5 is a vertical section taken along lines 5-5 of Fig. 1.

Patented Sept. 30, 1958 Referring now to Fig. 1 there is shown a dial assembly generally designated by the numeral 2 as it appears when embodied in a clock 4 (shown in phantom) provided with suitable hour and minute hands 6 and 8 respectively. The dial assembly comprises two dials 10 and 12 illustrated in enlarged size in Figs. 2 and 3 respectively. Dial 10 is provided with a plurality of perforated lugs 1d by which it may be fixed secured to the clock and is also provided with a central opening 16. Printed, engraved or otherwise established on the face of dial 10 are two systems of numbers. The numbers of the two systems differ in size and the order in which they are arranged. One system of numbers comprises a single series A of numerals (the larger size numerals) which' run clockwise with the last numeral l2 being placed in exact l2 oclock position. The second system of numbers runs counter-clockwise and comprises two series of smaller numerals B and C. The numerals of series B are disposed on a shorter radius than the numerals of series A. The numerals of series B, like the numerals of series A are spaced apart at angles of 30 degrees, but included in series B in place of the numeral 12 are the letters HR which comprise an abbreviation of hours The numerals of series C are disposed at the same radial distance as the numerals of series A but Voccur in radial alignment with the numerals of series B. The numerals of series C differ in value by increments of 5 and serve to provide a measurement of minutes. As is readily observed the letters MIN which comprise an abbreviation of minutes occur in place of numeral 60 in series C. A diamond-shaped starting index 20 is provided between the letters HR and MIN Running about the dial 10 outside of the numerals of series A is a plurality of radially extending indicants 22 graduated in divisions of 60. One of the indicants 22a coincides with a radius drawn through the center of starting index 2t). Others of said indicants, spaced from starting indicant 22a by multiples of 5, are in radial alignment with the numerals of series B and C. lndicant 22a is spaced from the exact l2 oclock position, that is, from center line CL of the dial, by an angle of 15. Since the numerals of series A are spaced from each other by an angle of 30, it is -obvious that starting indicant 22a and starting index 20 are disposed halfway between the numerals ll and l2 of series A. Stated another way the numerals of series A are displaced from adjacentnumerals of series B and C by an angle of 15, -occurring exactly half-way between successive ynumerals of series B and C.

Twenty-four of the indicants 22 are longer than the rest. Successive ones of the longer indicants are alternately spaced from each other by one and two of the shorter indicants, that is, by angles of l2 and 18 degrees. Thus, the larger numerals (series A) are positioned intermediate successive one of the longer indicants that are spaced from each other at an angle of 18 degrees and the smaller numerals (series B and C) are positioned between successive ones of the longer indicants that are spaced from each other at an angle of l2 degrees. For ease of description, four successive ones of the longer indicants are designated 22b, 22e, 22d and 22e.

The second dial member 12 preferably has a slightly smaller diameter. lt also has a center opening 24. In addition it has a radially extending arm 26 at its periphery. Twelve radially extending circumferentially arranged slots or openings 28 are provided in dial 12. Each opening 28 is determined by two long sides 30 and 32, each of which lies along a radius of the dial, and two shorter sides 34 and 36 which may be straight or slightly curved. A plurality of graduated indicants 38 and 40 are engraved, printed or otherwise provided on the surface of dial 12. The long indicants 38 are interposed between openings 28, two of such indicants being located between ones of said openings 28. indicants 41) are semicircular and are positioned along side 36 on the center line of each opening 28. A plurality of short arcuate lines 42 extend between adjacent opening 28 in intersecting relation with the inner ends of indicants 33. It is t be understood that the radially extending sides 30 and 32 of openings 28 are spaced from each by an angle equal to twice the angle between adjacent indicants 38. In addition, the angle made by each side 30 and 32 with the next immediately adjacent indicant 38 is the same as the angle between two successive indicants 38. This angle is 6 degrees. Consequently, semi-circular indicants 40 are also spaced from sides 30 and 32 by the same angle. Thus, indicants 38 and 40 and sides 32 and 34 cooperate to divide dial 12 into 6() graduated divisions in the same way that dial is divided by indicants 22.

Dials 10 and 12 and an intermediate spacer 45 are rotatably secured together by a sleeve 46 whose opposite ends are rolled over to form dial-retaining tlanges 48 and 50 as shown. This entire dial assembly is slipped onto the center arbor 52 of a clock 4 behind the hour and minute hands 6 and 8 respectively. The arm 26 of dial 12 is received by and extends through a circumferentially extending slot 54 provided in the case or shell of the clock (see Fig. l). Lugs 14 are attached to the clock by means of suitable screws so as to render dial 10 immobile relative to the clock. Dial 12, of course, is rotatable relative to dial 111 to the extent that arm 26 can be shifted in slot 54 in the clock casing.

The several functions of the dial assembly will now be explained.

Assuming that it is desired to utilize theclock in which the dial is mounted to tell the time of day or to provide a measurement of elapsed time, rotatable dial 12 is placed in the position illustrated in Figl 1. In this position the large numerals (series A) of dial 11i are displayed through openings 28. The other numerals (series B and C) of dial 1t) are masked by solid portions of dial 12. The indicants 22 on dial 1t) are also masked. Therefore, with dial 12 in the position of Fig. 1, there is Visible only a conventional clockwise extending scale comprising numerals 1-12 of series A for use with hour hand 6 and a plurality of indicants, sides 3G and 32 of openings 28 and markings 38 and 40, which eiectively subdivide dial 12 into 60 units for use with minute hand 8. The indicant 40a serves as a starting index to facilitate aligning of the minute and hour hands when it is desired to measure elapsed time as, for example, in determining how much time it takes to complete a given task.

Where the clock is to be used to indicate the expiration of a predetermined time, dial 12 is rotated to the position illustrated in Fig. 4. It is to be understood that the length of slot 54 is such that when arm 26 is moved from one end of thc slot to the other the dial 12 will be located automatically in one of the positions of Figs. 1 and 4.

When dial 12 is rotated to the position shown in Fig. 4, the large numerals of series A are covered and the numerals of series B and C are exposed to View through openings 23. ln this position indicants 38 and 4t? of dial 12 are in matched relation with the shorter indicants 22 of dial 10 and the sides of openings 2S are in identical matched relation with the longer indicants such as 22h, c, d and e of dial 10. The hour hand o will point to the numerals of series B and minute hand 3 will point to the numerals of series C.

With the dial 12 in the position shown in Fig. 4, it is an easy matter to determine when a predetermined period has expired. First, the hands ofthe clock are set to indicate the total time of the predetermined period. Thus, for example, if it is desired to perform a given operation of two hours, the hands of the clock would be turned until the minute hand coincides with zero index 20 (also indicant 40a) and the hour hand coincides with indicant 40h. The clock is then allowed to run. As the hands rotate in the regular clockwise direction they will automatically indicate in cooperation with the numerals of series B and C exactly how much time remains unexpired. When both hands are in alignment with zero index 20 it is an indication that the predetermined time period has expired.

The above described dial assembly may be embodied in any conventional clock or pocket watch and is especially adapted for use in a watch or clock provided with means for terminating movement of the hands when a predetermined period of time has elapsed. Such a timepiece is described and illustrated in our copending application Serial No. 542,656, filed October 25, 1955, for Timer Indicator Mechanism.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. Therefore, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts specifically described or illustrated, and that within the scope of the appended claims it may be practised otherwise than as specifically described or illustrated.

We claim:

1. A dial assembly for clocks comprising rst and second dials disposed in parallel coaxial relation, and means holding said dial together in rotational relation to each other, said rst dial having two systems of numbers on its face, the numbers of one system extending clockwise in the order of progressively increasing values and the numbers of the other system extending counter-clockwise in the order of progressively increasing values, the numbers of said one system being disposed alternately with the numbers of said other system, said second dial having a plurality of equiangularly spaced radially extending slots, one for each number of said one system, said second dial being rotatable between a first position whereat only the numbers of said one system are visible through said slots and a second position whereat only the numbers of said second system are visible through said slots.

2. A dial assembly for clocks comprising rst and second dials disposed in parallel coaxial relation to each other, and means holding said dials together in rotational relation to each other, said rst dial having rst, second and third systems of numbers on its face, the numbers of said first system extending clockwise in the order of progressively increasing values and the numbers of said second and third systems extending counterclockwise in the order of progressively increasing values, the numbers of said first and second systems having values corresponding to hours in the range of 1 to 12, the numbers of said third system having values corresponding to minutes in the range of l to 60, the numbers of said second system being disposed alternately with the numbers of said first system and in radial alinement with the numbers of said third system, said second dial having a plurality of equi-angularly spaced radially extending slots, one slot for each member of said first system, said second dial being rotatable between a first position whereat only the numbers of said first system are visible through said slots and a second position whereat only the numbers of said second and third systems are visible through said slots.

References Cited in the tile of this patent UNITED STATES PATENTS 839,578 Giroud Dec. 25, 1906 1,999,126 Gardner Apr. 23, 1935 2,201,941 Behr May 21, 1940 

